Northern Hayward Fault Network Overview
The Northern Hayward Fault Network (NHFN) is one of several networks of seismic instrumentation in northern and central California operated by the Berkeley Seismological Laboratory. Operations are partially supported by the USGS and by Caltrans. The NHFN is an array of borehole instrumentation deployed in the San Francisco Bay Area, with the goal of monitoring microseismicity on the Hayward fault. Data from these stations are transmitted to UC Berkeley using continuous telemetry and are analyzed for earthquakes. 7 sites are currently operational and additional stations are planned.
- Network Code
(also includes the
- Typical Station Equipment
3-component Oyo 4.5 Hz geophones
3-component Wilcoxon accelerometers
24-bit Quanterra digital data logger
Continuous telemetry to UC Berkeley
160 hour backup power supply
- Typical Recorded Channels
Sensor SEED Channels Rate (samples/sec) Sampling Mode FIR Filter Geophone EP1, EP2, EP3 100.0 Triggered Causal Geophone DP1, DP2, DP3? 500.0 Triggered Causal Accelerometer LL1, LL2, LL3 1.0 Continuous Acausal Accelerometer BL1, BL2, BL3 20.0 Continuous Acausal Accelerometer HL1, HL2, HL3 100.0 Continuous Causal Accelerometer CL1, CL2, CL3 500.0 Triggered Causal
Normally, only 3 channels of acceleration and the vertical component geophone are recorded and archived. In some cases, sensor failure has led to different recording combinations.
- Network State of Health
State of health is monitored through automated REDI alarm system
notifications, waveform evaluations of significant and repeating
small earthquakes and using SeisNetWatch software.
- Station and Channel Information
- Map of NHFN stations
- Table of NHFN stations
- BK Information Directory, including
- Information on Quanterra Timing Errors
- Data access
Waveform data from the BK network are available in
SEED format at the
Northern California Earthquake
Several tools provide access to SEED format data at the
NCEDC, both in terms of querying the archives and
allowing data requests.
- Querying the archives
- Access data through NCEDC web services
- Requesting data by channel and time
- Requesting data by event
Help on using these tools is available.
- Reports and Publications
- Reports on the NHFN from the Annual Report of the BSL:
- The NHFN has been developed by the Berkeley Seismological Laboratory in collaboration with:
- Broadband Stations
- Borehole Stations
- GPS Stations